Dear Unknown,
The Breech lock Channel closure comprises of lots of complicated components, (You must be well aware if u had designed) to seal & lock the high pressure compartment, which are required to be analyzed individually my considering combined effect.
The major advantage is that the Screw closure shares lots of load, thereby reducing shell thickness.
different companies have there different proprietary designs & different analysis methods.
I hope This solves your purpose.
_________________________
Tahir Quraishi
Technip